The invention concerns a vehicle seat and more particularly a vehicle seat incorporating spring support.
A form of vehicle seat which incorporates spring support comprises a seat squab supported on a base structure, and a spring arrangement for weight adjustment. The spring arrangement is connected to a weight adjustment actuating means. Such a vehicle seat, which can be typically used for example in trucks, tractors and building machines, can be adjusted for example to between 50 and 130 kg weight of the respective seat occupant, by means of the weight adjustment actuating means. In that respect however weight adjustment of the vehicle seat is effected only in accordance with the estimated weight of the respective seat user. If however the weight of the seat user has changed by virtue of that person gaining weight or losing weight or as a result of the weight of the clothing of the seat occupant, hitherto it has not been possible to implement optimum weight adjustment of the vehicle seat. That in turn has the consequence that the springing of the vehicle seat, that is to say the springing for the seat squab itself, in relation to the supporting base structure, is not set to its optimum. This therefore means that the springing of the vehicle seat is not implemented in the optimum range of oscillation movement of the vehicle seat. Either the springing of the vehicle seat by means of the spring arrangement provided for weight adjustment is set at too hard a value so that the oscillation travel or spring travel is above the optimum travel and the amplitude of the pivotal movement of the seat squab is small, or the spring arrangement is set at too soft a value so that the oscillation or spring travel is below the optimum value.
An object of the present invention is to provide a vehicle seat which permits simple actuation for adjusting the seat to the respective weight of the seat user in a very reliable and secure fashion in order to afford optimum vehicle seat springing.
Another object of the present invention is to provide a vehicle seat incorporating adjustable springing, which affords simple optimum adjustment of the springing effect of the vehicle seat for adaptation to the weight of the seat occupant.
Still another object of the present invention is to provide a vehicle seat incorporating a mechanism for adjusting the seat squab to the optimum position for operationally appropriate functioning of the spring arrangement supporting the seat squab, while affording simplicity of operation on the part of the seat occupant.
In accordance with the principles of the present invention the foregoing and other objects are attained by a vehicle seat comprising a seat squab which is supported on a base structure, with a spring arrangement for weight adjustment in respect of the seat squab, wherein a weight adjustment actuating means is operatively connected to the spring arrangement for weight adjustment. Associated with the weight adjustment actuating means is a level indicator means which serves to indicate the adjustment setting of the seat squab to the seat squab level or height optimally corresponding to the weight of the respective seat occupant in relation to the spring travel of the seat squab. The level indicator means and the weight adjustment actuating means are disposed at least substantially centrally at the edge of the seat squab which in use of the vehicle seat is the front edge thereof.
By virtue of the level indicator means in the vehicle seat of the invention, it is easily and reliably possible to accurately appropriately adjust the spring arrangement for weight adjustment, in such a way that accurate adaptation of the springing of the vehicle seat to the actual weight of the respective seat occupant is possible. In that case the weight adjustment actuating means is actuated specifically by the respective seat occupant until the level indicator means indicates the seat squab level which is the optimum setting in relation to the spring travel of the sprung seat squab. In that case the seat squab of the vehicle seat, in operation of the vehicle, performs a sprung movement in the optimum spring travel range.
The fact that, in accordance with the invention, the level indicator means and the weight adjustment actuating means are provided centrally at the front edge of the seat squab affords the advantage that the respective seat occupant is in fact sitting in the seat in the customary position in relation thereto during the weight adjustment procedure and is thus uniformly loading the seat squab, while the weight adjustment actuating means is readily accessible and can be actuated with optimum ease by virtue of its central arrangement at the front edge of the seat squab.
In accordance with a preferred feature of the invention the level indicator means includes an elongate flexible element disposed in a mechanically prestressed condition by means of a spring member between the base structure and the seat squab, and an indicator member operatively associated with the elongate flexible element.
In accordance with another preferred feature the elongate flexible element can include a pointer and the indicator member can have a viewing opening into which the pointer projects. In that case, the elongate flexible element can be formed by any suitable element such as for example a wire, a cable, a cord or the like. The pointer is suitably fixed to the elongate flexible element.
Preferably the viewing opening of the indicator member, into which the pointer projects, is provided at its edge with a marking which so-to-speak forms a scale. The marking can be formed by colored regions of different colors, symbols in combination with color markings, or other suitable forms of marker. For example the optimum range in respect of the seat squab level can be marked in green or yellow. A red area can be disposed adjoining that optimum range of seat squab level, to the right and to the left thereof respectively, in order to provide a simple indication that the vehicle seat is not at its optimum adjustment when the pointer is in one of the two red areas. The areas which are outside the optimum range of the seat squab level can also be clearly represented for example by the symbol of a small person and a large person respectively. It will be appreciated that it is also possible to envisage using other forms of marking or symbol.
In accordance with the invention therefore the indicator member can include a marking for the seat level or height which optimally corresponds to the respective seat occupant, in relation to the spring travel.
Likewise it is possible for the elongate flexible element to include a marker for the seat level or height optimally corresponding to the respective seat occupant, in relation to the seat travel, wherein the indicator member has a relatively small viewing opening for the elongate flexible element. While in the embodiment of the level indicator means set forth hereinbefore, with a pointer, the viewing opening of the indicator member is of sufficient longitudinal extent, in the last-discussed embodiment in which the elongate flexible element has a marker for the seat level optimally corresponding to the respective seat occupant, in relation to the spring travel, the viewing opening can be of relatively short size in order to provide a correspondingly accurate indication of the adjusted setting.
In a preferred embodiment of the invention, more particularly for example in relation to a vehicle seat of the kind last mentioned above, the elongate flexible element can be formed by a strip, with the indicator member having a viewing opening for the strip. Such a strip is simple to design, with suitable markings in the form of colored areas or in the form of icons, geometrical figures or the like.
In accordance with another preferred feature of the invention the indicator member can be provided at least substantially centrally at the front edge of the seat squab. A vehicle seat of such a design configuration enjoys the advantage that the seat occupant is sitting straight and thus in the customary position on the vehicle seat during the weight adjustment procedure, and is viewing forwardly and downwardly to look at the indicator member so that the respective weight of the seat occupant is in actual fact uniformly and symmetrically acting on the vehicle seat. For the same reason, another preferred feature of the invention provides that the weight adjustment actuating means is associated with the indicator member at the front edge of the seat squab, that is to say it is arranged centrally, because then, during actuation of the actuating means for setting the vehicle seat appropriately to the weight of the respective seat occupant, the seat occupant is sitting upright on the seat and is thus uniformly loading the vehicle seat.
In a preferred feature of the invention the weight adjustment actuating means can include a handle reciprocatable between an inactive position in which it fits around or closely encloses the indicator member and an active position of being spaced from the indicator member. In the inactive position the handle of the weight adjustment actuating means is not noticeable on the vehicle seat in such a way as to cause a nuisance or spoil the look of the seat. In the active position of being spaced from the indicator member the handle can be pivoted up and down with a pumping movement for example about a horizontal pivot axis through a defined pivot angle in order in that case to suitably adjust the spring arrangement of the vehicle seat in a stepwise manner. That can occur both in the direction of a light-weight seat occupant and also in the direction of a heavy-weight seat occupant, that is to say for example in a weight range of between 50 and 130 kg.
In accordance with another preferred feature of the invention the handle can be reciprocatingly displaceable between the inactive position and the active position by a linear movement, that is to say in the longitudinal direction of the seat, and in the active position the handle is pivotable up and down about a horizontal pivot axis for stepwise pumping adjustment of the spring arrangement provided for weight adjustment.
Another possible configuration according to the invention provides that the handle is displaceable with a reciprocating movement about a vertical axis between the inactive position and the active position and in the active position can be pivoted up and down about a horizontal pivot axis for stepwise pumping adjustment of the spring arrangement for weight adjustment purposes.
Further objects, features and advantages will be apparent from the description hereinafter of a preferred embodiment of the vehicle seat according to the invention.